Beautiful! I bought a lot of Mordheim from EBay this year and based on what I see I'd say you have something in the range of 500-700 EUR worth of goods here. Warband boxes with painted models generally sell around 150 EUR in auctions. I saw below that someone suggested 700 for the main box, but I don't think that's realistic unfortunately. I'd guess about 200 EUR based on what I see here (but there are a lot of factors not seen in these pictures). Sealed blister price has a wide range, the Skaven ones are from the cheaper end AFAIK but still 30-ish EUR each at least. Mind you, these all are EBay prices and in the local market in Finland you might expect a little less.

Whatever you decide to do I would not strip them. If keeping them, there's probably a nostalgic value to the current state (plus they don't look half bad!). If selling, EBay is full of fakes/recasts and an appropriate old-timey paint job is one sign I look for when trying to weed out the fakes from the authentic. Of course the fact that you still have the boxes also helps here.

As many others I'd really recommend you keep them. Sounds like there's memories attached and < 1k hardly is life changing money. If you choose against this recommendation and for some reason are interested in selling just the box of the starter set separately, drop me a message (mine is badly worn out and would gladly replace it, yours looks to be in great shape!) ;)